ARDEX P82 ULTRA PRIME For Non-Porous Subfloors, Wood & Cut Back High-strength, solvent free primer improves the adhesion of Ardex products over smooth, non-absorbent substrates such as ceramic and quarry tile, terrazzo, marble and steel decking. Also used over wooden subfloors. Mix red part A with white part B and apply with short-nap or sponge roller, leaving a thin coat of primer no heavier than a thin coat of paint. Do not use mops or spray equipment. Coverage 200-400 sq. ft. per gal.